120w valve amplifier.

[Mark Hennessy]

Looking really good, Andy

[Murphyv310]

Hi Andy.
I'd second Mark's comment. Really brilliant job. You must be proud and rightly so.

[Diabolical Artificer]

Thanks Gents. Praise indeed coming from two fettler's of renown.

Been mucking about this morning testing it yet again, not because it needs testing really but more to familiarise myself with the test gear I have. I'm trying out a few PC based spectrum analyser's and a program called REW, which is used for testing room acoustics ( it has a very good sig gen). I have a Marconi SA, which isnt working at present, but to be honest for what I use a SA for, Rtspect and Anaprof (both free) are more than adequate and easier to use for my purposes. I have two decent interfaces I use for recording, so have appropiated one for use with testing. I just need to knock up an attenuator so I don't fry the IP.

Previously I'd tested this amp at 1khz THD but tested it today at 100hz, 6khz, 10k and 20k, both sine and square. I tried to measure N and hum, but it's very low, my meter a Fluke bench DMM is having trouble getting a fix on it. I'll try a valve AC meter and my Marconi dist meter next. The sq wave looks good, though better at lower frequencies. Next I'm going to test for intermodulation distortion which I've not done before.

Like I said above, this testing is more about learning and having a fun twidling knobs than trying to improve the amp, though I have found a few things that I've tweaked. EG hum was quite bad so I re-routed the IP sig cable which improved things immensely.

I'll do another video soon as I know a few of you like to see progress. Thanks for your interest, Andy.

[Diabolical Artificer]

A few more pics of progress so far. I spent ages trying to paint the case British Racing Green with aerosols, in short it was a nightmare, couldn't get a decent finish. I ended up painting it with Hammerite but kept the two mono blocks as is. Also spent a hectic few days trying to fettle some brass D handles, as the place I bought a pair from ran out. trying to precision bend 3/8" brass bar was also a nightmare. This is after weeks of looking at every "4" Brass D handles" on the planet. After the failure to make four handles I looked online, and the shop had them back in stock. I've also had "interesting times" trying to find an identical  panel meter, nuff said. As Homer said looking skywards to Heaven "Your trying my patience baby!"

Anyhoo, onwards and upwards, I now have both PSU's done, both monoblock chassis made, one complete, one needs a OPT which I'm saving up for.

Andy.

[Crackle]

Very smart Andy.
I used some Halfords paint, Rover Brooklands green for a KB radio I converted to DAB and more recently for my KB 214 restoration. It is actually a lot darker than the photos on my thread.
Gloss is always difficult, it is all down to the preparation and priming. I always find it difficult to avoid runs.

Mike

[Diabolical Artificer]

It is difficult Mike, distance and temperature plays a part as well. I kept getting the orange peel effect which means lots of rubbing down, drying etc. Then there's dust or other debri that lands in your beautiful paint job. Next time if I can afford it I'd pay a proffessional with the kit or get it coated. Still it's keeps us out of trouble.

Andy.

[Terry]

As others have said, that is looking fantastic, Andy.

Having been in your back garden I'm not surprised you had problems with your first transformer - the very idea of trying to squeeze 243.3ft of wire into it even provoked a laugh from Helen when I read your post out to her!

[Diabolical Artificer]

Thank you . It was problematic Terry, kept twisting and getting tangled on bushes. The second one was a lot easier to do on the park.

Andy.

[Miguel Lopez]

Simply beautiful. Nice work!!!!

[Diabolical Artificer]

Thanks Miguel.

Andy.